F22B DOHC Compatibility

[preludeNinja]

Hey folks so when I bought my car I looked at the pictures and just assumed by the look that it was an H23 non vtec but when I was messing around with it today I noticed the block is stamped F22B. When I searched several sites for parts literally all I could find was for the SOHC F22. I tried searching some on here but everything just came up SOHC as well. I guess what I am asking about is the compatibility of H23 non vtec parts with this engine. The specs look identical not to mention the engines themselves look identical. Is the F22b just a JDM version of the H23 engine.

Thanks in advance.

[Jarrett]

It's similar, but very different in many ways. Both were offered in the trim level of Prelude beneath the VTEC model in their respective markets. The F22B is a Japan-only engine that came in the '92-'96 Prelude Si. It uses the same crankshaft, rods, valvetrain, intake and exhaust manifolds of the H23A1, but differences mostly stop there.

The block is the same casting as the F22A/B SOHC engines we have here. Same with the crankshaft and rods. The pistons are 85mm that are slightly less dished than ours to give the engine a resulting 9.3:1 compression ratio. The cylinder head is similar in design to the H23A1, but is based on 85mm diameter combustion chambers and with 6 oil drains (F-series) instead of 8 like the H-series engines.

The camshafts, while interchangeable with the H23A1, are a different profile. It's loosely held that the H23A1 camshafts are an upgrade for the F22B, but I don't think any real proof has been offered. I have a set of F22B DOHC cams, but no H23A1 camshafts to compare them to.

The timing assembly on this engine is pretty unique. The camshaft gears, as well as the lower timing gear and belt all have a different tooth count than the standard H23A1. There are ways around this, but to offer the best suggestion, I'd like to know what you currently have. Often, when used engines are installed, the timing belts are replaced. The way the previous owner dealt with that will determine what your options are going forward.

[Grumpys93]

The camshafts, while interchangeable with the H23A1, are a different profile. It's loosely held that the H23A1 camshafts are an upgrade for the F22B, but I don't think any real proof has been offered. I have a set of F22B DOHC cams, but no H23A1 camshafts to compare them to.

I have a set of H23A1 cams Jarrett, I can measure them for you, just tell me what parts your measuring and Ill do the same. Ill compare the cam gears when I get home, but I thought they had the same tooth count.

[preludeNinja]

Thanks for the great info! I will have to wait to get it open to figure out what the timing situation is.

[deevergote]

If you need a replacement timing belt, it IS possible to order the correct belt and other parts from overseas. As Jarrett mentioned, there are a few ways of doing it, but the correct parts (especially directly from Honda) are always the best.

[H311RA151N]

The H23A1 cams which I currently have installed in an F22B DOHC head are an upgrade over F22B cams.

Drummersetve7 & djcaz already took the specs of both sets of cams. I brought this up about a year ago and Drummersteve7 responded.

http://www.cb7tuner.com/vbb/showpost...7&postcount=36

I have H23A1 lower timing gear, water pump and cam gears. Route I went for the timing belt and such. Then of course an H23A1 timing belt.

[deevergote]

I'd like to see a second measurement done to corroborate. Camshafts are constantly rubbing against things, and that can result in wear.
Of course, it's probably more likely that the H23A1 would have higher mileage than the F22B, and therefore have camshafts that are worn more than the F22B's...

Still, one measurement of one set of camshafts isn't foolproof evidence.



I wonder why Honda doesn't mark their camshafts as clearly as other parts? So often, it's difficult to determine what's what (like base and Type S H22A cams. )

[Grumpys93]

for my set up I used bisimoto f22b cam gears, f22a water pump, h23 lower timing gear and Gates racing 1995 Integra GS-R. Its a tight fit but works.
I will try and get measurements tonight. I will be using a micrometer to do the measurements FYI.

[H311RA151N]

Most people go the route of F22B DOHC cam gears, F22A water pump, H23A1 lower timing gear and B18C1 timing belt. I didn't because when I bought the head it arrived with the cam gears broken off. The F22B DOHC cams were replaced with H23A1 cams primarily because both of my runout gauges indicated that the exhaust cam was slightly damaged likely from the same event that broke the cam gears. Neither of which was very thrilling.

I believe the only measurement taken of either set of cams as of yet is lift. it would be neat to see everything else. I still don't have mine together yet but I would like to know more of what to expect.

[preludeNinja]

Dang thanks for all the info everyone. I will look into the bisimoto stuff I have always been a huge bisi fan since highschool.

[Jarrett]

There's not much to be a fan of these days. And you might find his attitude to be a hard pill to swallow. But, if you're looking for aftermarket parts, he's really the only one.

[H311RA151N]

I'd like to see a second measurement done to corroborate. Camshafts are constantly rubbing against things, and that can result in wear.
Of course, it's probably more likely that the H23A1 would have higher mileage than the F22B, and therefore have camshafts that are worn more than the F22B's...

Still, one measurement of one set of camshafts isn't foolproof evidence.



I wonder why Honda doesn't mark their camshafts as clearly as other parts? So often, it's difficult to determine what's what (like base and Type S H22A cams. )

I had to check if I still have my F22B DOHC cams, and I do. I'm not as knowledgeable about figuring the specs out as Jarrett or Grumpys93 is. Heck Jarrett is who helped me figure out the F22B DOHC head in the first place. lol I'll read up and see what I need to do.

[preludeNinja]

There's not much to be a fan of these days. And you might find his attitude to be a hard pill to swallow. But, if you're looking for aftermarket parts, he's really the only one.

Wow yeah I see that now. It seems he's all about that Porsche now. I remember the engine shootout all the magazines did and he built an F22a NA for super street that was just insane. I hate to see that he has grown arrogant. Oh well I can still buy parts from him I guess haha.

[Grumpys93]

So my measurements for the h23 cams came out to
Intake: base circle 1.10" / lobe lift 1.326" so the lift is .226"
Exhaust: base circle 1.10" / lobe lift 1.325" so lift is .225"

Which is pretty close to drummersteve's measurements. I'm curious to see what Jarrett or hellraisen finds on the f22b cams.

[Jarrett]

Mine may be awhile. They're 3.5 hours away from me at the moment and I don't plan to be down there until next weekend.